The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Metal pollution in aquatic systems is considered a serious environmental issue globally due to their ability to accumulate in aquatic environments. Wetlands are vulnerable to this pollution as they are known to trap toxins, removing them from the water. Artificial mussel technology, originally developed for marine environments, was applied to this freshwater system and spot water samples were collected...
This paper investigates methods of magnet mass reduction in linear flux switching permanent magnet (LFSPM) machines by introducing tapered consequent poles. Based on the finite element analysis (FEA) three different models are designed, investigated and compared. The obtained results indicate that by adopting the proposed tapered ferromagnetic poles a considerable saving of material cost and weight...
In this paper a novel E-core Linear Variable Reluctance Vernier Hybrid Permanent Magnet (LVR-VHPM) machine with inherent magnetic gearing is proposed for use in the long stroke application of a wave energy converter. The proposed topology is a combination of a doubly salient flux reversal machine, a consequent pole machine and a surface mounted Halbach array Permanent Magnet (PM) machine. The stator...
Wave energy conversion can be simplified by using direct drive linear generators which may improve reliability. Numerous topologies of direct drive linear generators have been proposed in the last few decades such as the linear vernier hybrid permanent magnet (LVHPM) machine. However, the cost of this kind of machine is driven by the quantity of permanent magnet (PM) material. This paper proposes...
This paper proposes a new topology of a Linear Veriner Hybrid Permanent Magnet (LVHPM) machine with E-core stators and a segmented chamfered translator, which is shown to give mass reduction and better magnetic flux path compared to existing designs. Linear Permanent Magnet (PM) generators have the capability to reduce the number of moving parts, providing a simpler mechanical drive train when used...
This paper describes the thermal modeling approach of a permanent magnet alternator (PMA), developed to investigate the quantitative effect of thermal paste added into the machine end winding region. A thermal lumped parameter network is proposed to investigate the principal heat flow paths for a flange mounted alternator. The thermal model is implemented in Simulink, which allows many different heat...
This paper focuses on the improved thermal performance of electrical machines by increasing the conductor fill factor. A comparative design study of integrated starter generator (ISG) considering different pole/slot combinations and magnet topologies is used as a case study to fix slot dimensions. Compressed stator windings coupled with segmented stator structure are introduced to reduce copper losses...
With the increased electrification of aircraft, the use of motors to replace traditionally mechanical or hydraulic auxiliary systems has increased. Aerospace motor design has the rather unique characteristics of mass and torque density being extremely important, whereas cost is less so. For low maintenance, non-safety critical components, which are only used for short durations of the flight cycle,...
Reliable performance is of primary importance when designing machines for aerospace applications. In the case of generators, it forces thermal, electrical and physical isolation of phases and imposes a limit on short circuit current. Single tooth high inductance permanent magnet machines suit the application and have been in use for many years. However, the small slot clearance forces the use of labour...
This paper discusses coil pressing through which stator windings are compressed at high pressures to enhance the slot fill factor of electrical machines. Deterioration of insulation in compressed windings is investigated by performing quasi-static explicit dynamics finite element simulations. The results obtained from the proposed method are further investigated experimentally to validate the durability...
In this paper the design of a linear electrical machine for use with a free-piston engine will be discussed. Three conventional permanent magnet machines are compared to a flux switching and modulated pole machine. Each of the topologies is optimised to give a specific force whilst adhering to a limit on the mass of the moving component. Using simple vector analysis, it is shown that machine power...
The work presents a design methodology for a tubular Moving Magnet Linear Alternator for use with an External Combustion - Free Piston Engine (EC-FPE). Modelling and design of three alternative machines of 6 slots / 7 poles composed of feasible PM arrangements have been performed to react the same EC-FPE driving force. Demonstration of geometrical constraints and design methodology for the desired...
An induction generator has been designed for use in an open centred tidal turbine. Mechanical constraints in the turbine design enforces a large magnetic gap in the generator, which inherently limits the power factor. The large diameter of the machine means it is likely to be constructed out of a number of segments, which can each be modelled independently and approximated to either linear segments...
Fractional slot, concentrated-winding (FSCW) machines with saliency are being researched extensively for vehicle traction motors. However, they exhibit higher torque ripple than their equivalents without saliency. This paper identifies the origin of the torque ripple and explores potential solutions for its reduction through modification of the stator slot openings. The concept is demonstrated through...
This paper presents a case study for multi-variable and multi-modal design optimisation of a doubly fed induction generator (DFIG) based on surrogate-model optimisation algorithm. The DFIG's winding of stator and rotor are optimised to obtain higher efficiency for rewinding purposes. First, a Latin hypercube design is selected as the design of experiments to obtain sampling points. Then, the surrogate...
A novel V shape magnet motor has been designed in [1] for cost reduction compared to the existing surface-mounted in-wheel motor. The essential concept of this design is to remove the steel ribs on all ends of the magnets minimising the flux leakage. However, this approach poses a significant challenge on the structural aspect of the design. FEA was used to assess its structural integrity under various...
This paper tackles a fundamental weakness in all wave energy converters: the electro-mechanical power conversion. Initial progress on a project focusing on an all electric drive train with speed enhancement and power converter topologies is presented. Simulation results of three case studies are used to discuss the possibilities of speed enhancement in wave energy converter all electric power take...
The work is focused on investigating the performance of a linear alternator for use with external combustion — free piston engine. This family of engine can be powered either from renewable sources, scavenging waste energy from other sources of heat, or bespoke combined heat and power plants. Finite element analysis optimisation techniques followed by development of a Matlab/Simulink model were used...
This paper discusses a method for reducing cogging torque and harmonic content of back EMF waveforms in modulated pole machines (MPMs). Tooth pitching is applied to a separate phase MPM in order to reduce the most prominent harmonics present in a three-phase MPM's cogging torque. Experimental results show that the application of tooth pitching to these machines can reduce the cogging torque and back...
OpenHydro is developing open centred submerged turbines for the extraction of energy from ocean tides. Power take off is via a surface-mounted, radial-flux, permanent-magnet generator mounted to the rim of the turbine blades. A number of full scale devices have been deployed globally, upto 2MW and 16m diameter. The aspect ratio of the machines mean that end effects are likely to be significant and...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.